Spark-plug



L. ENRICHT.

. SPARK PLUG.

, 8. 1,357,768, Patented NOV. 2, 1920..

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LOUIS ENRICHT, OF FARMINGDALE, NEW YORK, ASSIGNOR TO ANNA ENRICHT, OF FARMINGDALE, NEW YORK.

SPARK-PLUG.

Application filed October 26, 1918.

1" 0 aZZ whom it may concern:

Be it known that I, LOUIS ENRIcH'r, a citizen of the United States, and a resident of Farmingdale, in the county of Nassau and State of New York, have invented a new and Improved Spark-Plug, of which the following is a full, clear, and exact description.

The invention relates to internal combustion engines and its object is to provide a new and improved spark plug arranged to securely hold a central electrode insulated in the plug body without danger of producing a short circuit. Another object is to dispense with the usual porcelain insulating tube for the central electrode and to provide insulation which is not liable to break, is cheap to manufacture and when placed in position in the plug forms a permanent art thereof. Another object is to provi e a spark plug which is not liable to be damaged by the explosions of the motive agent in the cylinder on which the spark plug is used.

With these and other objects in view, the invention consists of certain novel features of construction, as hereinafter shown and described and then specifically pointed out in the claim.

A practical embodiment of the invention is represented in the accompanying drawings forming a part of this specification, in which similar characters of reference indicate corresponding parts in both views.

Figure 1 is a sectional side elevation of the improved spark plug; and

Fig. 2 is a sectional plan view of the same.

The body 1O of the spark plug is provided with the usual threaded portion 11 for screwing the spark plug in the cylinder. The body 10 is provided with a central bore 12, preferably made conical and containing a core 13 made of an insulating plastic material which has set and hardened in the bore and adheres by frictional contact to the wall of the bore. The core 13 is preferably made of a plastic material such as ground mica, ground glass, powdered chalk, and kaolin, either of which is mixed with a suitable cementitious or binding substance such as casein, silicate of soda and the like. practice, I have found that chalk and sili cate of soda form an exceedingly efiicient and'cheap core. The insulating mass in a plastic state is poured into the bore 12 and is allowed to set and harden therein and around the central electrode 14 of the spark Specification of Letters Patent.

Patented Nov. 2, 1920.

Serial No. 259.844.

plug. The central electrode 14 forms the usual spark gap with the electrode 15 attached to the threaded end of. the plug body 10. The upper portion of the central electrode 14 is provided with a screw thread 16 a portion of which is embedded in the plastic material of the core 13 whereby a retaining means is provided for holding the electrode 14 against displacement in the core 13 after the latter has set and hardened. The upper outer end of the electrode 14 is provided with the usual binding means 20 for connection with a circuit wire. It will be noticed that the bore 12 and the core 13 are made conical with the bases lowermost so that the core is not liable to be forced out of the bore 12 by the force of the explosion in the cylinder on which the spark plug is used, but it is evident that I do not limit myself to the retaining means shown and described for holding the core 13 and the electrode 14: against displacement.

From the foregoing it will be seen that the spark plug can be cheaply manufactured and the core and the electrode practically form integral parts of the plug body. It will also be noticed that by the arrangement described the danger of producing a short circuit is practically eliminated as the hardened mass forming the core completely and efficiently insulates the electrode from the plug body; It will further be noticed that the core is not liable to break and is capable to withstand etficiently the force of explosions in the cylinder.

Having thus described my invention, I claim as new and desire to secure by Letters Patent A spark plug comprising a plug body having a bore therethrough and a core filling the said bore and set and hardened therein to adhere by frictional contact to the wall of the bore, the said bore and the said core being conical with the bases thereof at the bottom of the plug body, an electrode extending through the said core and having a screw threaded end, a portion of which is within the said core to hold the electrode against movement in the core, and binding means for an electrical conductor threaded upon the end of said electrode and arranged when in binding relation to bear against the end of the plug body for drawing said core into wedging engagement with said bore.

L GHTS ENRTCHT. 

